RADEON_P2PLL_REF_DIV
RREG32_PLL(RADEON_P2PLL_REF_DIV) & RADEON_P2PLL_ATOMIC_UPDATE_R);
while (RREG32_PLL(RADEON_P2PLL_REF_DIV) & RADEON_P2PLL_ATOMIC_UPDATE_R);
WREG32_PLL_P(RADEON_P2PLL_REF_DIV,
WREG32_PLL_P(RADEON_P2PLL_REF_DIV,